Review of Pharmacology - 9E (2015)

General

General Pharmacology 28 ReviewofPharmacology (b) Insulin binds to a receptor molecule on the outer surface of the plasma membrane and the hormone receptor complex activates adenylate cyclase through the Gs protein. (c) Insulin binds to a transmembrane receptor at the outer surface of the plasma membrane, which activates the tyrosine kinase that is the cytosolic domain of the receptor. (d) Insulin enters the cell and causes the release of calcium ions from intracellular stores. 124. True about G protein coupled receptors is: (AIIMS May 2008) (a) G proteins bind to hormones on the cell surface (b) All the three subunits alpha, beta and gamma should bind to each other for G proteins to act (c) G proteins act as inhibitory and excitatory because of difference in alpha subunit (d) G protein is bound to GTP in resting state 125. Which drug is not metabolized by acetylation? (AIIMS May 2008 AIIMS Nov 2006, AIIMS May 2003) (a) Isoniazid (b) Dapsone (c) Hydralazine (d) Metoclopropamide 126. Action of alpha subunit of G-protein is: (a) Binding of agonist (AIIMS NOV 2008) (b) Conversion of gdp to gtp (c) Breakdown of gtp to gdp (d) Internalization of receptors 127. All are second messengers except: (a) Cyclic amp (AIIMS NOV 2008, 2012) (b) Guanylyl cyclase (c) Diacylglycerol (d) Inositol triphosphate 128. A non-competitive inhibitor of an enzyme: (DPG 2009) (a) Increase Km with no or little change in Vmax (b) Decrease Km (c) Decrease Vmax (d) Increase Vmax 129. All known effects of cyclic AMP in eukaryotic cells results from: (DPG 2009) (a) Activation of the catalytic unit of adenylate cyclase (b) Activation of synthetase (c) Activation of protein kinase (d) Phosphorylation of G protein 130. All of the following drugs cause hemolysis in patients with G-6-PD deficiency except: (AI-2008) (a) Primaquine (b) Chloroquine (c) Quinine (d) Pyrimethamine 131. All of the following agents act by intracellular receptors EXCEPT: (AI 2007) (a) Thyroid hormones (b) Vitamin D (c) Insulin (d) Steroids 132. Regarding efficacy and potency of a drug, all are true except: (AI 2002) (a) In a clinical setup, efficacy is more important than potency (b) In the log dose response curve, the height of the curve corresponds with efficacy (c) ED50 of the drug corresponds to the efficacy (d) Drugs that produce a similar pharmacological effect can have different levels of efficacy 133. True statement regarding inverse agonist is: (AI 2001) (a) Binds to the receptor and causes intended action (b) Binds to the receptor and causes opposite action (c) Binds to the receptor and causes no action (d) Binds to the receptor and causes submaximal action 134. All are pharmacogenetic conditions except: (AI 2000) (a) Adenosine deaminase deficiency (b) Malignant hyperthermia (c) Coumarin insensitivity (d) G-6-PD deficiency 135. Which of the following property of the drug will enable it to be used in low concentration? (AIIMS Nov. 2005) (a) High affinity (b) High specificity (c) Low specificity (d) High stability 136. All of the following drugs are contraindicated in patients with G-6-PD deficiency, except: (a) Cotrimoxazole (AIIMS May, 2004) (b) Furazolidone (c) Nalidixic acid (d) Ceftriaxone 137. K m of an enzyme is: (AIIMS May, 2003) (a) Dissociation constant (b) The normal physiological substrate concentration (c) The substrate concentration at half maximal velocity (d) Numerically identical for all isozymes that catalyze a given reaction 138. Physiological antagonism is found in: (PGI Dec. 2007) (a) Isoprenaline and salbutamol (b) Isoprenaline and adrenaline (c) Isoprenaline and propanolol (d) Adrenaline and histamine (e) Salbutamol and leukotrienes 139. Drugs that should be avoided in G-6-PD deficiency are: (PGI Dec. 2007) (a) Chloroquine (b) Quinine (c) Sulfamethoxazole (d) Nitrofurantoin (e) Primaquine https://kat.cr/user/Blink99/

General Pharmacology 140. Phamacogenetics is associated with: (PGI Dec. 2005) (a) Variability of enzyme action (b) Environmental influence (c) Individual variability in oral absorption (d) Different mechanism of actions in different individuals (e) Different DRC in different individuals 141. Drugs causing SLE are: (PGI June, 2005) (a) INH (b) Hydralazine (c) Procainamide (d) Ranitidine (e) Phenytoin 142. Which of the following terms best describes the antagonism of leukotrienes’ bronchoconstrictor effect (mediated at the leukotriene receptors) by terbutaline (acting at the adrenoceptors) in a patient with asthma? (a) Pharmacologic antagonist (b) Partial agonist (c) Physiologic antagonist (d) Chemical antagonist 143. Which of the following terms best describes a drug that blocks the action of adrenaline at its receptors by occupying those receptors without activating them? (a) Pharmacologic antagonist (b) Non competitive antagonist (c) Physiologic antagonist (d) Chemical antagonist 144. Which of the following most accurately describes the transmembrane signaling process involved in the steroid hormone action? (a) Action on a membrane spanning tyrosine kinase (b) Action of a G protein, which activates or inhibits adenylyl cyclase (c) Diffusion across the membrane and binding to an intracellular receptor (d) Opening of transmembrane ion channels 145. Which of the following is most likely due to a pharmacogenetic condition? (a) Hypoglycemia by insulin (b) Tachycardia by albuterol (c) Metoclopramide induced muscle dystonia (d) Primaquine induced hemolytic anemia 146. Dose response curves of salbutamol for broncho dilation and tachycardia are widely separated on the dose axis. This information suggests that salbutamol is: (a) Highly potent cardiac stimulant (b) Highly efficacious bronchodilator (c) Highly toxic drug (d) Highly selective drug 147. Fastest acting receptor/transduction mechanism is: (a) Adenylyl cyclase – cyclic AMP pathway (b) Phospholipase C-IP3: DAG pathway (c) Intrinsic ion channel operation (d) Nuclear receptors 148. Which of the following is an inotropic receptor? (a) Muscarinic cholinergic receptor (b) Nicotinic cholinergic receptor (c) Glucocorticoid receptor (d) Insulin receptor 149. A partial agonist has: (a) High affinity but low intrinsic activity (b) High affinity but no intrinsic activity (c) Low affinity but high intrinsic activity (d) Low affinity and low intrinsic activity 150. Which of the following drugs act through heptahelical (serpentine) receptors? (a) Insulin (b) Estrogen (c) Local anaesthetics (d) Salbutamol 151. Which of the following does not act as second messenger? (a) Cyclic AMP (b) Inositol trisphosphate (c) Diacylglycerol (d) G proteins 152. ‘Drug efficacy’ refers to: (a) Effectiveness of drug in life threatening conditions (b) The maximal intensity of response that can be produced by the drug (c) The dose of the drug needed to produce half maximal effect (d) The minimum dose of the drug needed to produce toxic effect 153. A 56 yr old man, Surender with heart failure is to be treated with a diuretic drug. Drugs A and B have same mechanism of action. Drug A in dose of 50 mg produces the same magnitude of diuresis as 500 mg of drug B. This suggests that: (a) Drug B is less efficacious than drug A (b) Drug A is more potent than drug B (c) Drug A is a safer drug than drug B (d) Drug A will have shorter duration of action than drug 154. Which of the following has cytoplasmic receptor: (a) Epinephrine (DPG 2004) (b) Insulin (c) FSH (d) Cortisol 155. Which of the following is true for receptor action of a drug: (MPPG 2002) (a) An antagonist has both intrinsic activity and affinity for receptor (b) An antagonist has affinity but no intrinsic activity for receptor (c) A partial antagonist has no intrinsic activity or affinity for receptor (d) Intrinsic activity and affinity are not important for drug action 29 General Pharmacology https://kat.cr/user/Blink99/